A cooler has been conventionally used which is placed on a refrigerant pipe of a refrigerant circuit to cool a heat generating component, such as a power module, with refrigerant flowing through the refrigerant pipe (see, for example, PATENT DOCUMENT 1). Some of coolers of this type each include a heat transfer plate and a presser plate. The heat transfer plate has a groove into which a refrigerant pipe is fitted. The presser plate is configured to press the refrigerant pipe fitted into the heat transfer plate against the heat transfer plate to fix the refrigerant pipe.
In such a cooler as described above, when a refrigerant pipe is fitted into a heat transfer plate, and is pressed by a presser plate, thermally conductive grease is applied between the refrigerant pipe and the heat transfer plate to reduce the contact thermal resistance between the refrigerant pipe and the heat transfer plate, thereby enhancing the cooling performance. To facilitate placing the refrigerant pipe on the cooler, such thermally conductive grease is applied to a groove in the heat transfer plate not immediately before the placement but during manufacture of the cooler. To prevent the thermally conductive grease from being in contact with something and being removed, the cooler to which the thermally conductive grease has been applied and which includes a cover covering the groove is transported to the site of installation of the cooler, the cover is removed at the site of installation, and the refrigerant pipe is then placed on the cooler.